The Company of Light and Shadow
The region of the Upperdark beneath Shadowdale is known as the Shadowdark. It has served as a base for drow activities in Cormanthor since the attack on the Elven Court in –4,400 DR. The Shadowdark is roughly 120 miles in diameter, centered on the village of Shadowdale, and honeycombed with tunnels, subterranean lakes, springs, and areas of geothermic activity.
The whole Shadowdark complex seems to be controlled by the drow of house Dhuurniv.